This invention relates to the sealing of hydraulic systems against egress of the hydraulic fluid. The seal and method of the invention may be used to provide metal to metal seals on the internal portions of the hydraulic system or in sealing a hydraulic component to the hydraulic line. The hydraulic component may be a pump, compressor, hydraulic cylinder or the like.
Many hydraulic components are provided with a standard threaded female boss. Most connectors employed to connect the hydraulic component to the hydraulic line utilize some adaptor which screws into the threaded boss. It is necessary that a fluid-tight connection be made between the hydraulic component and its adaptor. A common prior art sealing method utilizes a rubber O-ring. However, the use of rubber or a similar polymeric material severly limits the adaptability of the system both as to temperature range and as to compatible hydraulic fluids.
In order to expand the operating conditions of a sealed hydraulic system, it has been proposed to employ a metallic V-ring seal to join metallic sections of fluid pressure systems. One such seal is described in U.S. Pat. No. 3,637,223. However, the use of such a seal creates problems in installation which may outweigh the benefits of a metal seal. In many applications it is desirable that the metallic components being sealed be mated by a screwing action. When such a mating relationship is employed with a conventional metallic seal, the tightening of the hydraulic components into sealing relationship results in the scratching or galling of the seal surface which in turn diminishes the integrity of the seal formed. For example, in the hydraulic coupling of U.S. Pat. No. 3,759,552, the parent of this application, a conventional metallic seal would prove unacceptable.
It is therefore desirable to provide a metallic sealing member suitable for use in hydraulic systems which will provide an acceptable metal to metal seal regardless of the manner in which the components of the hydraulic systems are mated in sealing configuration. In other applications, it is also desirable to provide a method of sealing hydraulic systems whereby the metallic sealing member may be deformed from its sealing configuration so as to be readily placed in the hydraulic system in sealing arrangement while returning to a tight sealing configuration at the operating conditions of the system.
The use of heat recoverable metals to form metal to metal couplings is disclosed in U.S. patent application Ser. No. 410,314, filed Oct. 29, 1973 as a continuation of Ser. No. 51,809, filed July 2, 1970 which in turn was a continuation-in-part of Ser. No. 852,722. That application was filed by J. D. Harrison and J. E. Jervis and is assigned to the assignee of the present invention, and the disclosure of that application is incorporated herein by reference. Heat recoverable alloys are disclosed in U.S. Pat. No. 3,753,700, issued Aug. 21, 1973 to J. D. Harrison et al. and assigned to the assignee of the present invention. The disclosure of that patent is incorporated herein by reference.